Burner



Fei.l 1935 E, A. RowE Er AL BURNER Filed Marchy 14, 1952 lneniozvs `Euene Rowe l Perg M. Fors-fer Patentedl Feb. l9, 1935 PATENT OFFICE BURNEREugene A. Rowe, Seattle, Wash., and Percy M. Forster, Berkeley, Calif.,assignors to Standard Oil Company of California, `San Francisco, Calif.,a corporation of'Delaware Application March 14, 1932, serial No, 598,688

' s claims. (ol. 15s-10s) welded objects, expanding hubs and wheelsprehmin'ary to shrinking them on shafts, and Work of similar nature. Itis particularly adapted for use with liquefied petroleum gas such aspropane, butane, and the like, and in combinationv with a cylinder orbottle of such liquefied gas constitutes an eiliecient and readilyportable heater.

An object of this invention is to provide a burner of the air inductiontype in which a source of compressed air is not required for efcientcombustion and the productionA of intense and lc calized heat.

Another object is to provide a torch or burner in which the source ofprimary air 'may be controlled and adjusted to suit the conditions ofgas pressure and llame size required.

Another object is to provide a torch which will direct a relativelysmall diameter cylinder of flame so that its disposition may be readilycontrolled.

A further object'is to provide a burner construction which will besimple, economical and easy to manufacture and in which 'adjustments forame size and gas consumption may be readily made.

Various other objects and advantages will be more fully apparent fromthe following description and drawing which illustrate a preferredembodiment of this invention.

The customary form of torch or burner of this nature and heatingcapacity foruse with illuminating or natural gas under low pressure mustbe `provided 'with compressed air in order to .supply suiiicient oxygenfor complete combustion of the gas. It is not always convenient oreconomical to provide a source of compressed air for a burner,particularly in small shops, or in remote localities such as loggingcamps, on board ships, etc.-

Because of the fact that the pressure available from natural orartificial gas mains is on the order' of a few ounces or at the most, lor 2 pounds per square inch, the construction of small socalledair-induction burners is such that they are not suitable for use withgasof higher pressure, such as the newly introduced bottled or liquefiedpetroleum gas. Most of these burners are of the customary Bunsen type inwhich the gas emerges from a small orifice or nozzle and is directedinto the center of a single large diameter Venturi tube or itsequivalent. -The aspirating effect of the gas is used to draw in as muchair as possible through the large iiared inlet end of the Venturi tube.No provision is made for the introduction of secondary air, which hasbeen found essential tc secure complete and efliecie'nt combustion inlarge torches, with high heat value gas under high pressure.

In other words, conventional burners larger than the customarylaboratory type, which are of the construction suitable for natural orartificial gas of low heat value, are not adapted to be used withliquefied petroleum gas. Elaborato 4and comprehensive tests with allcommercial burners available showed them to be unsuited to this fuel.Therefore, it is evident from the subjoined drawing and description thatthe burner of the present invention is a radical departure of thegeneral type of air-induction burners and that its novel feature is aprimary or premixing tube of very small diameter as compared with themain bodyv of the burner, in which the rapidly moving yjet of gasinspirates and mixes with the primary air for combustion. Secondary airis admitted to this mixture through holes in the outer casing of theburner and a completely balanced and intensely hot ame isproduced at thetip of the torch. The accompanying drawing shows a partial sectionalview of a torch or burner embodying the essential features of thisinvention. v

In this drawing, 1 represents the outer tube or body of the burner,which is preferably made of y cast bronze or other material which willresist oxidation, as it may be intensely heated for about 1,/3 of itslength. 'I'he tube 1 is preferably reduced to a somewhat smallerdiameter at its outermost end 'as at 2, in order to contract the llameand prevent its assuming a diverging conical shape. Secondary air p ortsare provided as at 3 and are preferably symmetrically arranged aroundthe circumferenceof the tube or body 1. The rear end of the tube or-body 1 is closed as shown at 4 and constitutes a support for the brassprimary airmixing tube 5 which isscrewed or brazed in place. It isessential that the tube 5 be concentric with the tube or body 1.

Two arms 6. extend from thelback of the body 1 and terminate in anannular boss or sleeve 7, which is drilled andthreaded concentric withthe tube 5. Adjustably mounted within the annular boss 7 is a brass g'assupply pipe 8, -which is threaded for a portion of its length as at 9and which extends completely through the boss 'I into the space betweenthe arms 6. A threaded lock nut 10 is provided to secure the adjustmentof the pipe 8 with respect to the boss '7.

An internally threaded brass cap 11 is mounted on the inner end of thepipe 8 and is drilled as at 12 to provide a single small diameteroriiice through which the gas ows and enters the tube aspirated may bevaried as desired by loosening the lock nut 10 and screwing the threadedportion-9 of the gas supply pipe 8 in or out of the threaded boss 7,thereby changing the distance between the tip of the gas orifice cap 11and the inlet end of the mixing tube 5. The size of the iiame and therate of gas consumption may be altered by substituting tips havingvarious size orifices.` If but one rate of gas combustion is desired theend of the pipe 8 may be swaged or brazed shut and an orifice drilleddirectly therein, care being taken to insure that it is concentric withthe tube 5. The length of the tube 5 and the number and location of thesecondary air ports 3, however, need not be changed for any i particularburner.

'I'he primary air mixing tube 5 is preferably supplied with slots 16spaced around its circumference and extending back a short distance fromthe outlet end. Other forms of openings may serve the same purpose butforconvenience and simplicity the use of slots cut by means of a hacksaw at 90 degree intervals is preferred.

It is not known exactly the theory on which these slots perform theirdesirable function which appears to result from a degree ofturbulenceset up between the primary air gas mixture and the secondary air, but inany event it has been found that the slotted tube causes the flame toburn farther back in the outer tube or body 1 and prevents the iiamefrom blowing out even under materially increased gas pressures.

As an example of this invention a torch was constructed with an outertube or body 1, which was of l/iinch thick material, 2 inches insidediameter and Sinches long, with an inner mixing tube inch insidediameter and 1% inches long, provided with 4 slots 16 approximately 11;inch wide and 1A; inch deep. Twelve secondary air ports 3 were locatedas follows: Two were diametrically opposite and 11A inches from the endof the burner, four were 90 apart around the circumference and 2%,inches from the end of th'e burner, four 'were similarly located 3%inches from the end of the burner, and two were diametrically oppositeand 4 inches from the end of the burner.

The tip of the burner tube or body 1 was reduced to 1H inches insidediameter at2. The gasl orifice tip 11 was drilled with a `inch diameterhole and was located 1/2 inch from the face of the closure 4. With theseproportions and a pressure of 20 pounds .per square inch of propane gas,approximately 4 pounds per hour of liquid propane 4were consumed. Asliquefied propane weighs approximately .4.45 pounds per lgallon and 1gallon will vaporize to approximately 38 cu. ft. of gas at atmosphericpressure and temperature, which gas has a heat value of approximately2,500 B. t. u.s per cu. ft., a total heat output of approximately 85,000B. t. u. per hour was obtained with perfect combustion. It was alsofound that a reduction in pressure to approximately 5 pounds per squareinch on the propane gas supply still resulted in an apparently perfectmixture and gave a smaller but intensely hotv blue flame.

Itwill be apparent that a number of modifications and changes could bemade in this arrangement without departing from the essential featurevof the invention which embraces all changes, variations, andsubstitutions coming within the scope of the appended claims.

We claim: a

1. In a burner for hydrocarbon gas, a cylindrical primary mixing tube ofsmall diameter, a secondary tube surrounding the primary tube andprovided with a plurality of radial secondary air ports near its outletend, closure means for the said secondary tube maintaining the tubes intheir respective positions, a bifurcated extension to said secondarytube terminating in an annular boss, an adjustable conduit secured insaid boss, said conduit terminating in a closure provided with a smalldiameter orice and adapted to direct a jet of gas at high velocity intothe primary tube thereby inspirating primary atmospheric air intosaidtube with the gas.

2. In a burner for burning inflammable gas with atmospheric air, a,hollow cylindrical body closed at one end, and having ports in itscylindrical wall near its outlet end, a tube inserted in the closed endof said cylindrical body concentric therewith and providing a passagetherethrough, said tube extending into said cylindrical body for aportion of the latters length and having slots in its outlet end, andmeans for introducing a jet of gas to said tube whereby a mixture of gasand air is drawn into said passage and burns as an axial -'fiame at theouter end of said cylindrical body.

3. A burner for hydrocarbon gas comprising a hollow cylindrical memberwith a closed end, an orifice in said closed end, a tube inserted insaid orifice and extending into said cylindrical member, saidtube havingslots through its wall adjacent its inner end, and means for directing ajet of gas into said'tube whereby a mixture of gas and air is drawn intosaid tube so as to burn at the open end of said cylindricalmember.

4. A burner for iniiammabie gas comprising a hollow cylindrical memberwith a closed end, ports in the cylindrical wall of said member, anorifice in the closed end of said member, a tube inserted in saidorifice and extending into said member, said tube having slots throughvits wall, a gas supply line terminating in a jet orice directed towardtheorice in the said cylindrical member andin spaced relationshipthereto, and means for adjusting said spaced relationship.

5. A burner comprising a hollow cylindrical member having one endclosed, a substantially straight, small Vdiameter primary airmixing tubeextending into the closed end of said cylindrical member, means adjacentthe inlet ofv said tube for injecting a high pressure jet ofair-inspirating gas therethrough, and ports through the wall of saidcylindrical member adjacent the end of said'tube and adapted to admitsecondary air radially to the air-gas mixture issuing from said mixingtube, the resulting mixture burning as an axial flame at the open end ofsaid cylindrical member. .y

6. A burner for higpressure hydrocarbon gas comprising a hollow`cylindrical member with a gas through said tube, lwhereby atmosphericair closed end, an orifice insaid closed end, 'a small is drawn intosaid-tube and mixed with saidgas diameter tube seated in said orice andextendso as to burn at the open end of said cylindrical ing inwardlyinto, said cylindrical member, said member. l member provided with portsintermediate its ends, l EUGENE A. ROWE. and means for directing a jetof high pressure PERCY M. FORSTER.

